Compensating device for carburetors



Nov. 14, 1967 P. D. NORCROSS 3,352,544

COMPENSATING DEVICE FOR CARBURETORS Filed Dec. 19, 1966 FIG. 4

, INVENTOR. PAUL D.v MUECEOSS A r roe/05x5- United States Patent '0 3,352,544 COMPENSATING DEVICE FOR CARBURETORS Paul D. Norcross, 1811 Warner Ave., Chicago, 121. 60613 Filed Dec. 19, 1966, Ser. No. 603,038 4 Claims. (Cl. 261-34) This invention relates to a device for compensating for wear in a carburetor and, more particularly, relates to a device for compensating for the wear between the acceleration pump shaft and the bore which receives the shaft.

Control of the flow of gasoline in a gasoline operated vehicle is typically done from a foot pedal at the drivers station. A complex linkage arrangement joins the carburetor to the pedal to provide for carburetor response as required. A carburetor typically includes an acceleration pump, which immediately responds to the foot accelerator pedal to inject a stream of gasoline into the carburetor to assist in accelerating the vehicle immediately without a time lag. The acceleration pump provides for immediate response of the vehicle to the omrators depressing of the accelerating pedal.

The acceleration pump is critical in that to be effective it must respond immediately. The pump is actuated through a shaft which is inserted in a bore within the carburetor casting. The force of the mechanical linkage between the foot pedal and the shaft wears the shaft and the bore causing a loose fitting relation therebetween. At such times as this loose relation occurs, the acceleration pump does not immediately respond to the operator and there is a resultant time lag in the response of the vehicle to the operator. This-time lag increases as the close fit between the shaft which is attached to the linkage and the bore in the carburetor housing or casting decreases.

The typical operator of a motor vehicle is not particularly skilled in engine operation and only recognizes the lack of response of the vehicle. The typical automobile service or repairman is generally not skilled in the operation of carburetors. Hence, the service or repairman who is called upon to remedy the lack of response of the vehicle to the operator must remove the carburetor from the engine and send it to a carburetor specialist. The specialist, recognizing the loose fit between the acceleration pump shaft and shaft receiving bore may then repair the carburetor and return it to the initial service or repairman. Of course, there is a great deal of expense to the operator of the motor vehicle in repairing this problem in this way in that a great deal of time and money is expended for the services of not only the specialist but also the general service man.

With these comments in mind it is to the elimination of these and other disadvantages to which the present invention is directed, along with the inclusion therein of other novel and desirable features.

An object of my invention is to provide a new and improved compensating device for carburetor wear of simple and inexpensive construction and operation.

Another object of my invention is to provide a novel compensating device for carburetors which compensates for the wear between the acceleration pump shaft and shaft receiving bore without the need for extensive disassembly of the carburetor and without the need for replacing the wom shaft or modifying the carburetor housing or casting at the receiving bore thereof.

Still another object of my invention is the provision of a new and improved compensating device for carburetors which may be installed by the operator of the motor vehicle as well as by the service or repairman without the need for any special tools and without the need for any adjustment of the carburetor after the device is installed.

A further object of my invention is the provision of a new and improved compensating device for carburetors which may also act as a booster for the acceleration linkage return spring.

A still further object of my invention is the provision of a device which quickly and conveniently corrects the lag in eflicient engine operation which may occur due to wear between the acceleration pump shaft and shaft receiving bore.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

FIG. 1 is a side elevation of a typical carburetor having my compensating device installed thereon with the dotted lines indicating a selected position of the linkage and with the acceleration pump shaft and shaft receiving bore portion broken away for clarity;

FIG. 2 is a perspective view showing the acceleration pump shaft and shaft receiving bore with my compensating device attached thereon;

FIG. 3 is a partial sectional view taken along the lines 3-3 of FIG. 2;

FIG. 4 is an enlarged sectional view taken along the line 44- of FIG. 3; and

FIG. 5 is a perspective view of the compensating device of my invention.

Onewform of the present invention is shown in the drawings and is described herein.

Referring to FIG. 1 the carburetor is indicated, in general, by numeral 10 and the compensating device therefore is indicated, in general, by the numeral 11. A portion of the linkage rod from the accelerator pedal is indicated by numeral 12 and is pivotally attached to accelerator plate 13 to provide reciprocating movement thereto in response to the foot pedal which is not shown here. Movement of plate 13 is in the direction indicated by the arrow 14. Accelerator plate 13 is attached at shaft 15 which provides for rotational movement of the plate about shaft 15 which is rotatably mounted in the carburetor Iii. In the dotted lines of FIG. 1, an arbitrary position of the linkage assembly is shown after manipulation of the foot pedal with the movement thereof transmitted through linkage 12 to the accelerator plate 13. The accelerator plate 13 rotates about shaft 15 causing upward movement of connecting rod 16 in the direction of arrow 16a to the position shown in the dotted lines. The connecting rod 16 is pivotally attached to plate 13 forming the pivot connection indicated at 17. The connecting rod 16 is journalled at the pivot connection 17 to accept a locking washer 18 which is a commercially available spring steel washer which snaps over the rod 16 to the journalled portion. Of course, a C clamp or an E clamp may also be used to perform this function. Connecting rod 16, at the other end thereof, is pivotally attached to angulated acceleration pump actuating or lever arm 19 at the pivot connection 20. The lever arm 19 is angulated as shown in FIG. 2 to enable pivotally receiving the connecting rod 16 in such a way that the thrust from the connecting rod 16 is distributed with a minimum of stress on the various pivot points on the linkage. Lever arm 19 is attached to acceleration pump shaft 21, for example, by a press fit therebetween. Shaft 21 rotates within shaft receiving bore 22 in carburetor 10 thereby providing bearing support for shaft 21. Shaft 21 may be constructed from cold rolled steel shaft material and bore 22 is provided in the housing or casting in any of several well-known ways.

My compensating device 11 is shown assembled to carburetor 19 in FIG. 1. The device comprises a shaft attachment member 23 which is adapted to be attached to the journalled portion at the pivot connection 17 of rod 16 providing for rotation at pivot 17. The attachment member 23 is generally rectangular in shape with an opening 24 therein, which opening approximates the diameter of the connecting rod 16 at the upper portion 24a and, at the lower portion 24b, corresponds to the diameter of the journalled portion of rod 16. This allows slipping of the shaft attachment member 23 over the rod 16 and locking at the lower opening 24b on the journalled portion of the pivoted connection 17 when upward tension is exerted on the shaft attachment member.

A spring or bias means 25 is connected to the shaft attachment member 23, and at the other end thereof, is attached to angulated acceleration pump arm attachment member 26 which, in turn, is attached to lever arm 19. As shown in FIG. 2, the angulated lever arm member 19 includes transverse portion 27 upon which member 26 may be hooked utilizing the hook portion 28 of attachment member 26. The tension of spring 25 retains the attachment member 23 on lever arm 19 and at connection 17 and thereby constantly urges lever arm 19 downwardly. Lever arm 19 is rigidly attached to shaft 22 and, consequently, the downward force of spring 25 on lever arm 19 is transmitted to shaft 21 which therefore, is

urged downwardly. As oftentimes occurs, movement be tween shaft 21 and bore 22 causes wear on the bore from the rocking motion exerted on bore 22 by shaft 21 each time the linkage is actuated. This rocking movement causes a poor fit to result between the shaft and bore and opening 29 results which represents the amount of wear on bore 22 and resultant poor fit between the bore and the shaft. V

The device of my invention exerts a constant pressure on shaft 21 through the linkage arrangement and maintains shaft 21 in a downward position as shown. Therefore, manipulation of the foot pedal will result in immediate response of the acceleration pump regardless of the size of the opening 29 created by wear of the shaft on the shaft receiving bore in the carburetor housing.

FIG. 2 schematically shows the acceleration pump 30 as it is actuated by shaft 21. Pump 30 provides for a stream of gasoline to enter the mixing chamber 31 through port 32 immediately in response to the slightest pressure on the accelerator pedal which movement is transmitted through the linkage assembly to shaft 21. A butterfly valve 33 controls the gasoline air ratio and is operably connected to the linkage from the accelerator pedal.

The position taken by shaft 21 after wear occurs and at such times as my compensating device is not secured on the carburetor is shown in dotted lines as the position taken responsive to the foot pedal motion transmitted through the linkage assembly. The dotted line position of shaft 21 shows the upward movement of shaft 21 to contact the upper portion of shaft 22 as indicated by dimension X. Rotation of shaft 21, and thus operation of pump 30, is not affected until the upward movement of shaft 21 is completed. Lever arm 19 therefore has moved upwardly within bore 22 immediately in response to the depressing of the accelerator at the operators station. Therefore, since the shaft has moved upwardly without rotating, an initial stream of gasoline is not forced into the mixing chamber 31 of carburetor 11 FIG. 3 shows the position of shaft 21 in solid lines as shaft 21 would appear with the compensating device of my invention properly installed as described above. In this instance bias means 25 urges shaft 21 downwardly and, even though there is wear, rotation of shaft 21 and thus operation of pump 30 occurs immediately in response to actuation of the foot pedal.

FIG. 4 shows the shaft as it would appear in shaft receiving bore 22 without being compensated for wear by the device of my invention. It can therefore be seen i that a great deal of upward movement, indicated by dimension X, takes place prior to shaft 21 being in a position to rotate and thereby actuate acceleration pump 30. Therefore, there is a considerable lag between depressing the accelerator pedal and injecting gas into mixing chamber 31.

In operation, the device of my invention is attached to a carburetor which exhibits the malfunction of a lag between depressing the accelerator pedal and the response of the vehicle. Member 23 is slipped over rod 16 onto the journalled portion thereof and pulled upwardly to properly secure member 23 at the pivot connection 17. Next, the 'bias means or spring 25 is pulled under tension and hook 28 is secured onto the transverse member 27. Therefore lever arm 19 is constantly being urged downwardly. The downward position of lever arm 19 urges shaft 21 downwardly and positions shaft 21 properly cradled with shaft receiving bore 22 at all times.

Since shaft 21 is in the proper position in receiving bore 22, as urged by spring means 25, response to the accelerator pedal is immediate. The accelerator pump which is actuated by the accelerator pedal through the linkages described above, does not lag since vertical movement of shaft 21 is substantially prevented by my compensating device.

From the foregoing it will be seen that I have provided a new and novel compensating device for a carburetor. My compensating device restores the operation of a complex carburetor to peak efficiency. Utilizing my compensating device, it is not necessary to overhaul or rebuild a carburetor in the event lag is experienced between depressing the accelerator pedal and the response of the vehicle. Further, the compensating device may be attached to the carburetor by a service or repairman of 7 minimum carburetor experience or by the vehicle owner who recognizes the symptoms of wear at the accelerator pump shaft receiving bore in the casting of the carburetor. Additionally, my compensating device acts as a booster for the acceleration linkage return spring thereby further improving the operation and performance of the carburetor without the need for extensive adjustment.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is:

1. In combination with a carburetor adapted for use.

with an engine having accelerator means operably connected to the carburetor, the carburetor having an accelerator plate pivotally mounted thereon and operably connected to the engine accelerator means,

a connecting rod pivotally mounted on the accelerator plate spaced apart from the pivotal mounting of the accelerator plate on the carburetor whereby rotation of the accelerator plate about the pivotal mounting in response to actuation of the accelerator means provides the connecting rod with a reciprocating, substantially vertical movement,

an acceleration pump aflixed in the carburetor, the pump adapted to inject fuel into the carburetor in response to the accelerator means,

an acceleration pump shaft operably connected to the acceleration pump and rotatably mounted in a shaft receiving bore in the carburetor and a lever arm connected, at one end, to the acceleration pump shaft, and at the other end, to the connecting rod whereby the acceleration pump is operably connected to the accelerating means and is responsive to the reciprocating movement of the connecting rod,

a compensating device comprising an attachment member attached to the accelerator plate substantially at the pivotal connection of the connecting rod to the accelerator plate,

a lever arm attachment member attached to the lever arm and bias means connecting said attachment member to said lever arm attachment member urging said attachment member and said lever arm attachment member together whereby the acceleration pump shaft is urged downwardly in the receiving here during reciprocating movement of the connecting rod cradling the acceleration pump shaft downwardly in the bore thereby permitting immediate response of the acceleration pump to the accelerating means and compensating for wear in the acceleration pump shaft receiving bore.

2. The compensating device of claim 1 wherein said attachment member is attached to the connecting rod at the pivotal connection of the connecting rod to the accelerator plate, the connecting rod having a journalled portion positioned at the pivotal connection of the connecting rod to the accelerator plate, the attachment member having an opening therein with an upper portion corresponding to the diameter of the connecting rod and a lower portion corresponding to the diameter at the journalled portion of the connecting rod whereby said attachment member may be positioned on the connecting rod at the journalled portion thereof with said bias means urging said attachment member upwardly positioning the small portion of the opening in said attachment member in engaging relation with the journalled portion of the connecting rod.

3. The compensating device of claim 1 wherein said bias means connecting said attachment member to said lever arm attachment member comprises a spring.

4. The compensating device of claim 1 wherein said lever arm attachment member includes a hook portion attached to the lever arm at the end of the lever arm opposite the end attached to the acceleration pump shaft.

References Cited UNITED STATES PATENTS 2,615,694 10/1952 Olson 261-34 X HARRY B. THORNTON, Primary Examiner. TIM R. MILES, Assistant Examiner. 

1. IN COMBINATION WITH A CARBURETOR ADAPTED FOR USE WITH AN ENGINE HAVING ACCELERATOR MEANS OPERABLY CONNECTED TO THE CARBURETOR, THE CARBURETOR HAVING AN ACCELERATOR PLATE PIVOTALLY MOUNTED THEREON AND OPERABLY CONNECTED TO THE ENGINE ACCELERATOR MEANS, A CONNECTING ROD PIVOTALLY MOUNTED ON THE ACCELERATOR PLATE SPACED APART FROM THE PIVOTAL MOUNTING OF THE ACCELERATOR PLATE ON THE CARBURETOR WHEREBY ROTATION OF THE ACCELERATOR PLATE ABOUT THE PIVOTAL MOUNTING IN RESPONSE TO ACTUATION OF THE ACCELERATOR MEANS PROVIDES THE CONNECTING ROD WITH A RECIPROCATING, SUBSTANTIALLY VERTICAL MOVEMENT, AN ACCELERATION PUMP AFFIXED IN THE CARBURETOR, THE PUMP ADAPTED TO INJECT FUEL INTO THE CARBURETOR IN RESPONSE TO THE ACCELERATOR MEANS, AN ACCELERATION PUMP SHAFT OPERABLY CONNECTED TO THE ACCELERATION PUMP AND ROTATABLY MOUNTED IN A SHAFT RECEIVING BORE IN THE CARBURETOR AND A LEVER ARM CONNECTED, AT ONE END, TO THE ACCELERATION PUMP SHAFT, AND AT THE OTHER END, TO THE CONNECTING ROD WHEREBY THE ACCELERATION PUMP IS OPERABLY CONNECTED TO THE ACCELERATNG MEANS AND IS RESPONSIVE TO THE RECIPROCATING MOVEMENT OF THE CONNECTING ROD, A COMPENSATING DEVICE COMPRISING AN ATTACHMENT MEMBER ATTACHED TO THE ACCELERATOR PLATE SUBSTANTIALLY AT THE PIVOTAL CONNECTION OF THE CONNECTING ROD TO THE ACCELERATOR PLATE, A LEVER ARM ATTACHMENT MEMBER ATTACHED TO THE LEVER ARM AND BIAS MEANS CONNECTING SAID ATTACHMENT MEMBER TO SAID LEVER ARM ATTACHMENT MEMBER URGING SAID ATTACHMENT MEMBER AND SAID LEVER ARM ATTACHMENT MEMBER TOGETHER WHEREBY THE ACCELERATION PUMP SHAFT IS URGED DOWNWARDLY IN THE RECEIVING BORE DURING RECIPROCATING MOVEMENT OF THE CONNECTING ROD CRADLING THE ACCELERATION PUMP SHAFT DOWNWARDLY IN THE BORE THEREBY PERMITTING IMMEDIATE RESPONSE OF THE ACCELERATION PUMP TO THE ACCELERATING MEANS AND COMPENSATIONG FOR WEAR IN THE ACCELERATION PUMP SHAFT RECEIVING BORE. 